In the conventional manufacture of integrated circuit modules such as are described above, the module is constructed in two separate phases. In the first phase, an IC manufacturer fabricates an IC chip of a very small size which is then mounted in a larger package containing protruding leads to be soldered to a printed circuit board (PC board). The most commonly used package is a dual in-line pin package (DIP). The IC chip prior to packaging is of such a small size that electrical connections are made to it with a wire-bonding apparatus which utilizes a microscrope to locate the proper contact points on the IC chip. During manufacture, the IC chip is mounted on a conductive lead frame, the electrical interconnections between the chip and the lead frame are then made with the wire-bonding unit, and the chip is hermetically sealed in an encapsulating medium. The leads of the lead frame in the DIP package protrude a short distance out of the encapsulating medium and are then bent down so that they may be soldered to a PC board during final assembly of the IC module.
In phase 2 of the assembly, a PC board of the required shape is manufactured requiring the well known steps of masking a copper-plated substrate and etching the copper away from the unmasked portions of the board to produce the required printed circuitry. The contact edge of the board is shaped for insertion into a PC board edge connector, and during etching the circuit board is provided with copper lands in spaced relation along the contact edge for contacting the electrical connector. The circuit board is then drilled to accept the leads from the DIP package containing the desired IC. The IC is then inserted and soldered to the PC board.
While quite suitable for moderate volume production of integrated circuit modules, this conventional two-phase manufacturing process of the IC module requires a large number of individual steps which may be eliminated by the use of the present invention. For example, it will be noted that the IC chip is first electrically connected to the lead frame in phase 1, and then the lead frame is soldered to the PC board in phase 2, whereas in the present invention the second step in this method is eliminated, and no soldering is required.